AnsweredAssumed Answered

vrf 16 bit Comms

Question asked by VRFuser on Dec 2, 2003
> need to send 16 bits of data with 1 stop and 1 start bit.
> However, the Direct I/O will only allow us 8 bits.
> Any ideas on how to overcome this?

Bummer man! Unfortunately non-standard hardware begets non-standard
hardware. All the way down to the core of Windows, serial communication is
based on between 4 to 8 bits per byte. I'm no hardware expert, but I'm
pretty sure that every 8250 compatible solution ever invented does the same.
I'm afraid you're really stuck on this one. There just isn't any Wintel
hardware that will do that.

Probably your best option is to build your own box that takes two bytes from
the printer port and shift-registers 'em out over your serial lines. In
effect, just build a bigger 8250. If you emulate the printer handshake you
can use CreateFile / ReadFile / WriteFile to communicate with your hardware.
Otherwise you can use the port IO thingy.

You could do it with software alone by toggling a bit on an existing
parallel port, but you'd have to get a real-time kernel for Windows to make
it reliable and write your own driver. Not a real pretty thought.

I'm curious: did this hardware come out of the navy?
-SHAWN-


---
You are currently subscribed to vrf as: rsb@soco.agilent.com
To subscribe send a blank email to "join-vrf@it.lists.it.agilent.com".
To unsubscribe send a blank email to "leave-vrf@it.lists.it.agilent.com".
To send messages to this mailing list,  email "vrf@agilent.com". 
If you need help with the mailing list send a message to "owner-vrf@it.lists.it.agilent.com".

Outcomes